华北地区基岩热储回灌段地温场变化特征及热源分析

Variation Characteristics of Geothermal Field and Heat Source Analysis of Bedrock Thermal Reservoir Recharge Layer in North China

选取华北平原区典型基岩地热田—献县地热田作为研究对象,对基岩热储回灌井进行了垂向温度场监测,论述了供暖季后回灌井地温场的变化特征,并根据获取的地热地质数据对基岩热储回灌段温度恢复的热源进行了综合分析。研究结论表明:供暖季内持续的低温回灌会造成回灌井内回灌段热储温度大幅降低,并且在非供暖季内热储温度恢复速率缓慢;献县地区供暖季后基岩热储温度恢复的主要热量是热储层外围同层相对高温的地层传导以及同层相对高温地热流体流动所带来的热量;华北基岩热储集中开发区更应该合理布设开采井与回灌井,以增加热储有效使用寿命。

Based on the study of Xianxian geothermal field,a typical bedrock geothermal field in the North China Plain,the vertical temperature field of the bedrock thermal reservoir reinjection well is monitored,and the variation characteristics of the geothermal field of the reinjection well after the heating season are discussed,and the heat source of the temperature recovery in the reinjection section of the bedrock thermal reservoir is comprehensively analyzed.The research result indicates that continuous low-temperature reinjection during the heating season can cause a significant decrease in the thermal storage temperature in the reinjection section of the reinjection well,and the recovery rate of the thermal storage temperature is slow during non heating seasons.The main heat source for the recovery of bedrock thermal storage temperature in the Xianxian area after the heating season is the conduction of relatively high temperature strata around the thermal storage layer and the heat brought by the flow of relatively high temperature geothermal fluids in the same layer.The concentrated development zone of bedrock thermal storage in North China should be more reasonably arranged with extraction and recharge wells to increase the effective service life of the thermal storage.